[shmaster]

To answer some of the question on various factions in this novel:

Spoiler:

The netherworld and Virie are enemies. Netherworld creates Megalo to fight the Masou Shoujou.
But there are fake Megalo created by King of the Night to attack Eu.

Virie is ruled by an ambitious queen who tries to expand her rule using Virie's technology. Dai Sensei tried to rebelled against her along with Chris 100 years ago but failed.
Chris was cursed by the queen and became an old man, thus she bares huge hatred toward Dai Sensei who was not cursed. She was plotting to steal the power of the people who have gathered in this city to fulfill her revenge.